Protective layers based on nanoscale particles are known from the following publication: “Thermische Aufbringung neuartiger Korrosionsschutzschichten für Leichtmetalle auf der Basis oxidischer Nanopartikel” [Thermal application of novel corrosion protection layers for light metals based on oxidic nanoparticles], H.-Q. Nguyen, W. Fürbeth, M Schütze, Karl—Winnacker-Institut of DECHEMA e. V, Frankfurt am Main, the disclosure of which is incorporated herein by reference in its entirety. Protective layers based on polymeric or particulate sols are disclosed, which can be applied onto a workpiece surface as a sol by simple mechanical coating techniques such as dip and spin coating. The resulting protective layers are purely inorganic, transparent and curable or sinterable even at a low temperature and have a high microhardness in addition to a very good corrosion protection effect.
Protective layers based on nanoscale particles are already applied onto glass and plastic surfaces, in order to provide-them with a water- and dirt-repellent surface (i.e., a lotus effect).
The use of protective layers based on nanoscale particles for producing scratch-resistant varnishes for automobile paint is also being studied.
In recent years, the need has likewise arisen in the semiconductor industry to protect unencapsulated semiconductor chips particularly against mechanical damage such as scratches in a simple and reliable way.
There are two reasons for this need. On the one hand, unencapsulated semiconductor chips are handled in a semiconductor assembly as an inherent result of the process. On the other hand, in particular package types, so-called “bare dice” or unencapsulated semiconductor chips are used which remain unencapsulated, for example, in order to improve the heat transport out of the semiconductor chip or in order to minimize the space requirement of the semiconductor component. Both cases entail the risk that the corresponding semiconductor component will become damaged by scratches, particularly as a result of handling.